Secondary batteries, advanced systems

The United States launched an advanced communications satellite known as the INTESAT-IV system in the 1990s, which represented a fourth-generation commercial communications satellite, incorporating the latest radiofrequency and digital components with minimum weight, size, and power consumption. This system offers specified communications service requirements and can be used in support of future manned space flight missions. Frequency operating bands and secondary battery power requirements for this particular communications satellite are summarized in Table 2.15. 

In the case of multicarrier operation, back-off power is required, which tends to lower the DC-to-RF efficiency for the TWTA units to around 25%. Under such operation, the secondary batteries must be able to supply DC power in excess of 1,200 W for the TWTAs alone. Low-power TWTAs are deployed in DSCS-III systems because of high-gain antennas and the integration of advanced technologies in the receivers. 

As with the primary battery systems, significant performance improvements have been made with the older secondary battery systems, and a number of newer types, such as the silver-zinc, the nickel-zinc, nickel-hydrogen, and lithium ion batteries, and the high-temperature system, have been introduced into commercial use or are under advanced development. Much of the development work on new systems has been supported by the need for high-performance batteries for portable consumer electronic applications and electric vehicles. Figure 22.1 illustrates the advances achieved in and the projections of the performance of rechargeable batteries for portable applications. 

Currently, Yardney is in continuous production of secondary lithium-ion batteries, primary and secondary silver-zinc batteries and primary reserve silver-zinc batteries used on various Department of Defense applications. The primary battery applications include the Navy s Trident IID5 Fleet Ballistic Missile program, the Minuteman III ICBM, and primary power for the MK 21 re-entry vehicle. In 2012, the Trident II missile has achieved 143 successful test launches since 1989—a record unmatched by any other large ballistic missile or space launch vehicle. The most prominent Li-ion batteries made by Yardney have powered the Mars Explorer Rover missions (Spirit, Opportunity, and Curiosity), the USAF B-2 Bomber and Global Hawk aircraft, and the US Navy Advanced SEAL Delivery System (ASDS). One of the future applications for Yardney s Li-ion batteries is NASA s Orion Crew Exploration Vehicle (CEV). 

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